During oil drilling and production, signals may be sent along a pipe for communication with down-hole devices such as detectors. Such signals can be sent along a communication channel which follows the path provided by the pipe. There are also other applications than oil drilling and production in which signals are sent along the path provided by a pipe. An electrical signal can be sent along an electrical cable. Wired pipe technology exists for a drill pipe in which an electrical cable is provided inside the pipe and inductive couplers are provided at the pin and box ends of the pipe. The inductive coupling provides an electrical connection from one pipe section to a second pipe section when the two pipe sections are connected together. This connection is an electrical pathway for signals travelling both ways through the pipe string. The transmission rate is in practice typically limited to 56 Kbits/second. The limited data transmission rate prevents real time communication of detailed data generated down hole to the surface. Those data can only be retrieved later when the drill string or other pipe is pulled back to surface.